You can claim a credit for federal excise tax you paid on fuels you used:
Off-highway business use doesn't include use in a registered highway vehicle.
You must report the credit you claim as income on Schedule F if both of these are true:
Also, you might deduct the total cost of fuel you use on Schedule C for off-highway business use or commercial fishing. If so, you must report the amount you claim as income on Schedule C.
To claim this credit, complete Form 4136: Credit for Federal Tax Paid on Fuels at www.irs.gov.